Create account form with vertical form appearance

Similar to the login form (change 55847), this presents a compact
vertically-stacked form, if a global variable is set or if you add
?useNew=1 to the query string.

The redesigned create account form also:

* Removes the remember me checkbox (see bugzilla 47267)
* Displays some wiki statistics in a benefits column.
* Repositions the FancyCaptcha image if present using JavaScript (see
  bugzilla 47372).
* Sets the template skin as in change 59577.

Backported from master for new opt-in Create account form.

(cherry picked from commit af7b20570c9df15c1ee059cccb21acaee2119957)

Bug: 44628
Bug: 47267
Change-Id: I9b03d519af43de147bff0ac509a1154f67cd3a0a
Merge "Create account form with vertical form appearance" into wmf/1.22wmf2